Field of Invention
The present invention relates to a lighting system, including at least one luminaire and with its respective lamp control module. More particularly, the present invention relates to a centralized and hot pluggable power system with redundant power source, at least one luminaire having the features of small size, light weight, low electromagnetic interference (EMI), long lifetime, and easy to maintain; and a lighting system employing the above luminaire.
Description of Related Art
Lighting devices play an important role in human life, and may be applied in various areas such as in a building, in a vehicle, or on a decoration article. Lighting device is not only an illumination tool but has great impact on human daily life.
Common lighting devices include incandescent lamps, fluorescent lamps, light emitting diode (LED) lamps, etc. In a conventional incandescent lamp, electricity is conducted through tungsten filaments to generate light by high heat. However, such incandescent lamp consumes a lot of power, and hence a fluorescent lamp is becoming a substitute of incandescent lamp.
A fluorescent lamp generally applies high voltage on electrodes to emit electrons hitting mercury vapor atoms for generating ionization and excitation phenomena. When the mercury vapor atoms return to an original state from an excitation state, an electromagnetic wave of 253.7 nm in wavelength is emitted, wherein the wavelength of 253.7 nm is in an invisible light wavelength range. Thereafter, various fluorescent materials can be used to absorb and convert the electromagnetic wave into visible light, such that the fluorescent lamp may emit various colors of light in accordance with the fluorescent materials.
For achieving the goals of energy saving and environmental protection, a light-emitting diode (LED) module is developed. When a LED is under a proper forward voltage, electrons and holes are respectively injected to N and P terminals. Then, energy is released in the form of light when the electrons drop to a basic state from an excited state at the P/N junction, thereby enabling the LED to emit light.
The LED requires a DC current, and hence LED lamps generally include an AC-to-DC converter inside for converting AC to DC current. In general, a common AC-to-DC converter is a switching type. Even with a better power conversion ratio, the switching inverter is bigger and has the worse EMI, causing LED lamps to have a larger size and complicated design to pass safety regulations. Further, the lifetime of LEDs is longer than that of other electronic elements within the AC-to-DC converter, such as the electrolytic capacitor. Therefore, if the AC-to-DC converter could be disposed outside, the luminaire shall have longer lifetime and the AC-to-DC converter shall be easier to maintain.
Therefore, there is a need to develop a lighting system in smaller size with lower EMI.